The increased attention given to improving patient safety is critically important for all areas of medical practice. Surprisingly, there remains a paucity of information related to patient safety in the ambulatory care environment. Emergency departments (ED), in particular, require attention because they are high hazard settings and are likely to be the most unsafe area for patients. The complexity of the emergency care delivery system is a result of the many people, decision points, and overlapping processes of care that must be integrated both within and outside of the department. Many processes are tightly coupled and time dependent, requiring sequential and efficient performance to achieve safe, successful outcomes. Importantly, there has been no thorough analysis of errors and adverse events that is detailed and comprehensive enough to establish safety priorities for the ED. In order to reduce the risk of adverse events, studies must first be performed to clearly identify the types of events that occur and to understand the elements that lead to them. The aims of this project are to: (1) identify errors and adverse events in the ED through active surveillance; (2) compare errors and adverse events identified through active surveillance with those identified through the standard reporting mechanism; and (3) use Failure Mode and Effect Analysis (FMEA) for medication management processes that are identified as highest risk. In the first two aims, errors will be identified and categorized by type and will further include time of day, departmental census and staffing levels to ensure both event detail and system context. The FMEA in Aim 3 will be based upon medication management processes identified in Aims 1 and 2. This approach will allow comprehensive, systematic, prospective and retrospective analyses to identify, characterize and categorize errors, both active and latent, that occur in the ED. This valuable information will provide a basis for the future direction of developing effective interventions. This project is relevant to the care that occurs during the nearly 110 million annual visits to EDs in the United States. Since there is so little known about the errors and adverse events within the ED, the knowledge gained through this study will be used to assist in the development of a safety agenda for the specialty of Emergency Medicine. [unreadable] [unreadable] [unreadable]